The worried father understood that when school officials said they were putting his teenager through a threat assessment, what they meant was “We think the next school shooter could be your son.”

Like almost every parent who sends a child to a school in America these days, Mark feared the next school shooting. He wanted to believe the school’s threat assessment system would help make sure Portland wasn’t the next Parkland.

So when a police officer came to his home without a warrant, Mark welcomed him inside. He handed over the family guns despite having no legal obligation to do so.

He told his nerdy, logical 16-year-old to be patient and remember what Spock from Star Trek always said: “The needs of the many outweigh the needs of the few.”

Be open, show you have nothing to hide, let the process work and you’ll be cleared, Mark thought. Yet here he was, about to bring his family bad news: Parkrose High still considered his son a threat.

As he pulled into the driveway, three neighborhood boys played outside before dinner, the way boys do, with toy guns.

How, Mark wondered, do you tell the difference between a normal interest in guns and a dangerous one?

As the body count from school shootings has risen, school officials across the nation have been forced to consider versions of this question. Administrators use detailed protocols and checklists to examine the circumstances of students who may pose risks.

The pressure to prevent the worst has grown as students have begged adults to make sure they aren't next to die. In a nation divided over gun control, school threat assessments offer another option: Find a way to control the student.

It’s uncomfortable territory for educators. They’re acutely aware that if they overlook the smallest sign, the consequences could be devastating and irrevocable.

To protect student confidentiality, those formal threat assessments are highly secret. But one Oregon family agreed to allow an unfettered view into their case as it unfolded. The family provided documents and records of meetings with school officials and allowed a reporter into their home for extended periods over several months.

They did this, they said, because they hoped making visible the experience of undergoing a threat assessment would inform the debate about how to keep students safe. What happened to their son sheds light on how the desire to thwart a shooting can have unintended consequences.

Beth Nakamura | The Oregonian/OregonLive

Sanders plays video games in his room.

Because of the sensitive nature of the topic, The Oregonian/OregonLive is not publishing the family’s last name and refers to the son by his middle name, Sanders.

Inside the house, Sanders sat on the sofa under silver letters hung with care: “This Home Believes.” He was lit by the green glow of a tank that housed a bulbous goldfish Sanders named Bakuhatsu, the Japanese word for explosion.

The first thing Sanders wanted to know was if his dad had gotten a copy of the complaints against him. His school’s nervousness about Sanders was fueled by heightened fear after the school shooting in Parkland, Florida left 17 dead. But why Sanders had come under scrutiny in the first place was mysterious. One, maybe two people from “the community” had written the school a week and a half after Parkland, a school official told them. The family had also heard a rumor that a student had said Sanders goes by the nickname “Shooter.” Sanders told officials no one had ever called him that.

What if the catalyst for all this was simply bad information?

Mark had read, several times over, the email from the school district’s student services director, Michelle Markle, outlining what the school district was willing to say:

“We won’t share the actual email from the concerned parent with you. However, I can tell you the content mainly had to do with these two things:

-dress/attire/appearance

- fascination, obsession with guns, knives, etc.”

Markle and other key Parkrose officials declined numerous requests to speak to The Oregonian/OregonLive about Sanders’ case, even though the family waived all privacy rights and put in writing that the district should speak candidly about their son.

“We stand firm in our commitment to the privacy of our students, staff and families,” Markle wrote in an email. “Schools and districts have the difficult challenge of weighing the rights and needs of the individual student against the rights and needs of the school as a whole.”

It was easy to figure out why the teen’s attire worried people. Sanders’ signature piece of clothing was a big black trench coat.

Years ago, Mark gave Sanders the riding coat he picked up on a youthful adventure in Australia. Sanders loved the weight of the coat. As a person on the autism spectrum, he welcomed the heaviness. It provided comfort in a world that often overwhelmed him. He wore it no matter the weather. With pride, he would note that when it gets above 85 degrees, it will be 104 degrees inside the coat, a fact he learned in science class. He was so associated with the coat that one time he didn’t wear it, he was marked absent by mistake. Sanders eventually wore out Mark’s old coat and his grandma got him a new one for Christmas.

Beth Nakamura | The Oregonian/OregonLive

The family dog sleeps on Sanders' trench coat.

Now, what had begun as a beloved hand-me-down, an armor that made Sanders feel secure and protected from the world, made him vulnerable.

It was hard for Mark to see his son in pain, and although the school district’s email had stressed that Parkrose officials "care greatly" for his son, Mark felt they weren’t really seeing Sanders.

Instead, they saw a symbol, another kid in a trench coat, whose hair could be a little greasy some days, who was blunt and impatient when he felt others weren’t following the rules.

A kid who maybe fit a “profile” that evoked the moment in American history that everyone remembers each time a school shooting makes the news: Columbine. The two angry young men who killed 13 people at their Colorado high school had worn long black dusters, and rumors flew that they were part of a “Trench Coat Mafia.” While the lore around the trench coats was later debunked, it became a key part of the myth that surrounds the tragedy. Ever since, there has been inevitable unease about any male student viewed as a loner who wears a long dark coat.

Beth Nakamura | The Oregonian/OregonLive

Some of Sanders' various collections. From left: silhouettes of weapons, some realistic some fantasy, that he made out of wood; toy space ships; an assortment of knives from his room; his toy Nerf guns.

But his son, he felt, didn’t fit that profile. He is a boy who loves to figure out how things work, who adores the family dog, a picky eater who insists on sprinkling every dish with shredded cheese and spritzing it with honey before eating it.

Mark told Sanders he still didn’t have a copy of the complaints or the report from the officer who had come to their home. Instead, he’d been told that to stay in school, Sanders had to agree to be randomly searched at any time. He would also be under something called discreet supervision and need to check in and out with someone at the school each day.

Also, he couldn’t bring his scissors to school anymore.

“They’re scissors!” Sanders groaned. “If they want that to happen, then they better put some left-handed scissors there.”

“Then you get some left-handed scissors that don’t have sharp points on them and you don’t sharpen them to a point,” Mark replied.

“I never sharpened them, Dad.”

Sanders handed over the scissors for his dad to inspect. Mark held them up by their gummy handles and squinted. The blades, about the size of a small pair of fingers, were covered by a plastic guard. Mark looked closer.

It was possible, Mark thought, that Sanders had sharpened the scissors as the school claimed. Sanders went to a blacksmithing class after school and could make swords and knives. Still, there had been a lot of misunderstandings about the scissors. At some point, someone at the school had mistakenly thought they were a knife. School officials made a big deal out of the fact that Sanders, when asked if the scissors were a weapon, noted they could be.

This response should not have surprised anyone familiar with autism, Mark told himself. Because of his disability, Sanders took most things literally. He struggled to understand others and had trouble making himself understood.

Beth Nakamura | The Oregonian/OregonLive

The scissors Sanders brought to school that raised concerns.

Sanders’ favorite class, the one he needed the scissors for, was theater tech. He cut cloth used for scenery. Now, Sanders felt nervous about going. A power drill, Sanders told his parents, could also be a weapon. He didn’t know if simply building a set for the next musical would freak everyone out.

Sanders had been drawn to theater because his school had no woodshop class. He loved to build, to study the way things worked. His parents suspected their naturally handy son might want to go to a trade school and make a career out of it.

Now, Sanders’ main interest, the skillset Mark saw as Sanders’ potential ticket to a steady paycheck and a normal life, was under scrutiny.

Sanders felt so antagonized by the pressure of the suspicions, some days he skipped school. His parents worried whether he would even graduate.

Mark told Sanders that he tried to convey to school officials how jarring this had been for Sanders. Sanders, Mark told them, wanted to “punch out” whoever complained.

“And you said I’m making it worse!” Sanders chuckled.

It seemed to Mark that this system risked making a student who wasn’t violent, violent. What if this system created the very thing it was trying to prevent?

Sanders felt singled out and criminalized. Mark couldn’t blame him. He found it hard to explain the threat assessment process to a son who demanded the world make sense in concrete terms. But he tried to distill what Markle had told him at this latest meeting.

“She is not willing to say that there is no threat or no risk in the same respect that you could not say that a pen is not a weapon,” Mark told him. “There is always some level of risk.”

“They need to understand that their protocol doesn’t help things it makes things worse,” Sanders responded. “Have they understood that yet?”

“No.”

“Then they are idiots! They should not be in charge of the school.”

“Sanders, wait. No, they don’t understand that yet. You and I and Mother, through this process, are trying to bring them to that understanding. OK?”